package PTA.Pta_ch02;
import java.util.Scanner;
public class ex28 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        float x= sc.nextFloat();
        float y = sc.nextFloat();
        float a;
        a=y/x;
       if(n<a)
       {
           System.out.println("0");
       }else{
           System.out.println((int)(n-a));
       }
    }
}
